Internal combustion engine in a sound-proof casing

ABSTRACT

An internal combustion engine in a sound-proof casing supported by means of sound-proofing stays extending through the soundabsorbing casing upon a foundation, to which a supporting frame designed as a rigid framework is attached by means of soundproofing members, the wall members forming the sound-proofing casing being attached to said supporting frame.

United States Patent [191 Thien et al.

[ Jan. 1,1974

INTERNAL COMBUSTION ENGINE IN A SOUND-PROOF CASING Inventors: Gerhard Thien; Othmar Skatsche;

Heinz Fachbach, all ;of Graz, Austria Assignee: Hans List, Graz, Austria Filed: Sept. 27, 1972 Appl. No.: 292,802

US. Cl. 181/33 K Int. Cl. F02b 77/00 Field of Search 181/33 K; 123/198 E References Cited UNITED STATES PATENTS 7/1938 Grutzner 181/33 K UX 111/1966 Dear et al. 181/33 K UX 8/1972 Fachbach et al 181/33 K 3,695,386 10/1972 Thien et al 181/33 K FOREIGN PATENTS OR APPLICATIONS 567,567 2/1945 Great Britain 181/33 K Primary ExaminerRichard B. Wilkinson Assistant Examiner-John F. Gonzales Attorney-Watson, Cole, Grindle & Watson [5 7 ABSTRACT 10 Claims, 11 Drawing Figures PATENTEDMN Hm 3.782.496

sum 30F4 v PATEN JAN H974 SHEET l 0F 4 INTERNAL COMBUSTION ENGINE IN A SOUND-PROOF CASING The invention relates to an internal combustion engine in a sound-proofing casing comprising a supporting frame of the rigid type surrounding the engine to which wall members forming the sound-proof casing are attached.

According to a known design, a motor generator as sembly is located inside a sound-proof casing comprising a box-type frame formed by angle sections to which plate-shaped wall members consisting of sandwich-type sheet metal are attached The motor generator assembly is supported by means of two parallel angle-section stays arranged at the base of the casing with the interposition of sound-proofing shim plates. The casing proper, supported by sound-proofing brackets rests upon the foundation. Unformtunately, however, the bottom portion of the sound-proof casing has to carry the entire weight of the motor generator assembly so that it must be of a certain strength. Moreover, a comparatively large portion of the engine vibrations is transmitted to the casing-supporting frame in spite of the soundabsorbing support of the assembly. In addition, the sandwich-type wall members are relatively expensive to produce.

It is an object of the present invention to avoid these shortcomings by providing an internal combustion engine located in a sound-proof casing of a design ensuring a high degree of sound-absorption at moderate expense. According to the invention, the engine is supported by means of sound-absorbing stays extending through the sound-proof casing and resting on the foundation, the supporting frame for the sound-proof casing being attached to the engine proper by means of sound-proofing members. The sound-proof attachment of the casing-supporting frame to the engine independently from the engine location provides excellent sound-proofing between the casing and the engine, so that the wall members constituting the casing can be made of simple sheet metal, plastics or light-metal casting to be coated with a vibration-absorbing layer in special cases only. Of course, it is also possible to use sandwich-type sheets without having to resort to soundproofing measures between the two layers as is generally necessary.

Since the sound-proof casing has no carrying mission, the supporting frame may be somewhat thinner and lighter than usual.

According to another embodiment of the invention, the wall members of the sound-proof casing are preferably attached to the supporting frame with the interposition of packing strips extending alongside the outer rim of the wall members. This oil-tight construction of the sound-proof casing makes it possible to install an internal combustion engine featuring crankcase walls with weight-reducing large-size cutouts, for example. In that case the casing proper provides the oiltight shell of the engine. However, sealing means are needed where the engine stays extend through the casing walls.

According to the invention the wall members are attached to the supporting frame by different means depending on given requirements. For example, according to a further embodiment of the invention, the supporting frame can be formed by hollow sections of a square cross-section and the wall'members can be provided with stiffening strips on the inside alongside their outer rim, designed, for example, as profile strips with legs attached to the wall members and bent outwardly at right angles and screwed to the hollow sections with their web portions adjoining the packing strips. This design excels by its particular stiffness and the plain construction of the supporting frame whose hollow sections can be interconnected in a simple manner at the corner points of the casing by welding.

According to another feature of the invention the wall members are bent Z-fashion at their outer rim and engage with the leg of their outer rim extending parallel to the plane of the wall in a slot of the packing strip of a preferably square cross-section. Adjoining the packing strips are longitudinal angle irons held in position by means of clamps screwed to the supporting frame in spaced relation to each other. With this embodiment of the invention no metallic contact prevails between the wall members and the supporting frame, so that the sound-proofing effect of the casing is still further increased.

According to a further embodiment of the invention the outer rim of the wall members can be bent inwardly and then outwardly similar to a semicircle and engage with its bent-up portion in a longitudinal groove-like recess of the packing strip and spaced clipper-like gripping levers can be attached to the supporting frame, each engaging with a hook-like projection on the inside of the outwardly bent rim portion of the wall members. Consequently, the wall members can be readily removed from the supporting frame if required so as to provide access to the internal combustion engine for attendance and adjustments.

According to a further embodiment of the invention, the wall members consist of an essentially flat outer wall and an inner wall attached thereto by means of outwardly bent corrugated projections. The inner wall presents an inwardly protruding corrugation extending parallel to the outer rim of the wall member, said corrugation engaging a groove-shaped recess of the packing strip, the wall members being held in position by means of bolts screwed into tapholes of the supporting frame and preferably countersunk in embossed recesses of the wall elements. This stiffening of the wall members helps avoid resonant vibrations of the casing.

Finally, according to yet another embodiment of the invention, at least one of the wall members of the sound-proof casing is non-detachably connected with the supporting frame or integral with same. This type of easing makes it possible to have such parts of the engine as do not require permanent attendance and need not, therefore, be directly accessible, covered by means of the associated wall member. In addition to simplifying the overall construction of the casing this provides an effective reinforcement of the supporting frame and a certain reduction of weight.

Further details of the invention will become apparent from the following description of several preferred embodiments of the invention with reference to the ac- FIG. 4 is a partially cross-sectional view of the casingsupporting frame according to the first-mentioned embodiment of the invention,

FIG. shows the construction according to FIG. 4 as indicated by the arrow V in FIG. 4,

FIGS. 6 and 7, FIGS. 8 and 9, and FIGS. and 11 illustrate corresponding variants of the casingsupporting frame, as related to FIGS. 4 and 5, respectively.

The internal combustion engine shown in FIGS. 1 and 2 presents brackets 2 on the crankcase sidewalls by means of which it rests via sound-proofing members 3 on the foundation (not shown). The engine 1 is surrounded by a box-type supporting frame 4 attahced to additional brackets 6 and 7 provided on the crankcase with the interposition of sound-proofing members. The brackets 6 and 7 are located near the lower rim of the crankcase sidewalls and have horizontal bearing surfaces for the associated sound-proofing members 5. The bracket 7 is attached to the upper portion of the crankcase sidewalls opposite the fuel injection pump 8 and presents a vertical bearing surface for the soundproofing member 5.

In the embodiment of the invention shown in FIGS. 1 and 2 the supporting frame 4 consists of hollow sections 9 of a square cross-section joined at the corner points of the supporting frame 4 by welding.

On all of the six outer surfaces of the supporting frame 4 essentially plate-shaped wall members 10, 1010" are attached with interposition of packing strips 11 extending alongside the outer rim of the associated wall member. The wall members 10, 10' and 10" together form a sound-proof casing 12 surrounding the internal combustion engine. The two engine supports 2, 3 extend through the wall members 10' and 10" respectively and are sealed off against same by means of gaskets 13. The exhaust connection 14 of the internal combustion engine 1 also extends through the wall member 10" and is sealed off against same by means of an additional gasket 15. To improve the accessibility of the fuel-injection pump 8, the wall member 10" is provided with a cutout covered by a removable cover 16 sealed off by means of a packing 17.

The wall member 10" mounted on the flywheel end of the engine 1 has a cutout' for the passage of the flywheel flange l8 sealed off against the wall member 10" by an additional gasket 19. The flywheel flange 18 is surrounded by a cowl 20 (only partially shown in the drawing) attached.- to the wall member 10" with the interposition of a circumferential joint 21. This cow] is particularly used where the engine 1 serves to drive any assembly accommodated in a sound-proof casing such as a compressor 22 shown in FIG. 3.

The invention is similarly applicable to the compressor assembly 22 shown in FIG. 3. For that purpose, the compressor is also surrounded by a supporting frame 4' which like the supporting frame 4 consists of hollow sections 9' and is attached to the compressor 22 by means of sound-proofing members (not shown in the drawing). Wall members attached to the supporting frame 4'similarly define a sound-proofing casing I2surrounding the compressor 22. The apertures of the two casings I2 and 12' facing each other, through which the shaft 23 for the drive of the compressor 22 extends, are sealed off against the outside by means of an annular sleeve 24.

FIGS. 4 and 5 illustrate the attachment of two wall members 10 to a hollow section 9 of the supporting frame. Inside the wall members 10 stiffening strips 25 are provided extending alongside their outer rim and 5 designed as U-shaped strips with legs 26 bent outwards at right angles and attached to the wall members 10. The packing strips 11 rest upon the outer surfaces of the hollow sections 9. The wall members 10 are screwed to the hollow section 9 by means of bolts 27 passed through bores of the web portion 29 of the stiffening strips 25 with the interposition of a circlip 28.

Another method of attaching the wall members 10 is illustrated in FIGS. 6 and 7. The wall members 10 are bent Z-fashion at their outer rim and engage with wallparallel legs 30 of their outer rim in a longitudinal slot of packing strips 31 of a generally square cross-section. Adjoining the exposed longitudinal edge of the packing strips 31 are longitudinal angle sections 32 held in position by means of spaced clamps 33 screwed to the frame strips 36 of C-shaped cross-section of the supporting frame by means of screws 34 with the interposition of circlips 35. Thus any direct metallic connection is precluded between the wall members 10 and the frame strips 36.

According to the design shown in FIGS. 8 and 9 the outer rim of the wall members 10 is bent inwardly and then outwardly generally in the shape of a semicircle. With their bent-up portion 37 the wall members 10 engage a groove-like recess of the packing strip 38 of a generally trapezoid cross-section. The cross-section of the frame strip 39 is designed as an angular section with legs 40 extending in perpendicular relation to each other with outwardly bent ends 41 and a web portion 42 located between the legs 40 and forming an angle of therewith. Attached to the web portion 42 are longitudinally spaced gripping levers 44 by means of rivets 43. Each of the gripping levers engages in a hook-like extension 45 inside the bent-up rim portion 37 of the wall members 10. Adjacent gripping levers 44 are arranged in inverse relationship to each other and engage alternatively in the upper and lower wall member 10. Therefore, the wall members can be easily disassembled by opening the respective gripping levers 44.

As shown in FIGS. 10 and 11, the wall members 10 consist of an essentially flat outer wall 46 and a spaced inner wall 47 attached with outwardly bent corrugated projections 48 to the outer wall 46. The walls 46 and 47 are interconnected also alongside their outer rim 49. The inner wall 47 has an inwardly protruding corrugation 50 extending parallel to the outer wall 49. The corrugation 50 engages a groove-like recess of a packing strip 51 of a generally rectangular cross-section. The wall members 10 are attached to the frame strips 54 forming the supporting frame by means of screws 52 with the interposition of a circlip 53 and braced against the packing strips 51. The heads of the screws 52 are countersunk in recesses 55 of the wall members 10.

I claim:

1. An internal combustion engine in a sound-proof casing comprising a supporting frame surrounding the engine and attached thereto, sound-proofing members arranged between said supporting frame and its attach ments to the engine, the supporting frame being designed as a rigid frame, wall members attached to said supporting frame and forming a sound-proof casing for the engine, sound-proofing stays mounted on said engine and extending through said sound-proofing casing,

said stays resting on a foundation carrying the engine.

2. An internal combustion engine according to claim 1, comprising packing strips located between said supporting frame and said wall members and extending alongside the outer rim of the wall members.

3. An internal combustion engine according to claim 2, comprising a supporting frame consisting of hollow sections, stiffening strips arranged on the inside of said wall members and extending alongside the outer rim of the latter, said stiffening strips adjoining the packing strips and being screwed on to said hollow sections.

4. An internal combustion engine according to claim 3, wherein said hollow sections have a rectangular cross-section and said stiffening strips are designed as U-shaped strips with legs bent outwardly at right angles and a web portion located between the legs, the said angle-shaped legs being attached to the inside of the wall members and the web portion adjoining the packing strip.

5. An internal combustion engine according to claim 2, wherein said wall members have an outer rim bent out Z-fashion, a first leg of this outer rim extending in transverse relation to the wall plane of the wall member, the second external leg extending in parallel relation to said wall plane, said packing strips being of a rectangular cross-section and each presenting a slot extending in a longitudinal direction of the packing strip and in parallel relation to the wall plane of the adjacent wall member, said second leg of the outer rim of the wall member engaging said slot of the packing strip, angle irons extending longitudinally and adjoining said packing strip, clamps provided in spaced relation to each other on the supporting frame and screwed to same, said clamps engaging the angle irons and holding the latter together with the packing strips on the supporting frame.

6. An internal combustion engine according to claim 2, wherein said wall members have a profiled outer rim, a first section of this outer rim being bent inwardly, the second section adjoining the former section of the outer rim being bent up in the shape of a semicircle, said packing strip having a groove-like recess extending in a longitudinal direction of the packing strip and being located on the side of the packing strip facing away from said carrying frame, the section of the outer rim of the wall member which is bent up in the shape of a semicircle engaging the groove-like recess of the packing strip, clipper-shaped gripping levers arraged in spaced relation to each other on said supporting frame, a hook-shaped projection at each of the gripping levers engaging the inside of the rim section of the wall member bent up in the shape of a semicircle.

7. An internal combustion engine according to claim 2, wherein each of the wall members consists of an essentially flat outer wall and an inner wall essentially parallel to the former, the inner wall comprising a number of outwardly bent corrugated protrusions and being attached to the outer wall by means of the corrugated protrusions, one corrugation being protruding inwardly on the inner wall of the wall member and extending in parallel relation to the outer rim of the wall member, said packing strip having a groove-shaped recess extending in a longitudinal direction of the packing strip and being arranged on the side of the packing strip facing away from the supporting frame, said corrugation engaging the groove-shaped recess of the packing strip, a number of holes being provided on said wall members in spaced relation to each other next to the corrugation, a number of tapholes in said supporting frame in alignment with said holes, fixing bolts extending through the holes and screwed in the tapholes of the supporting frame.

8. An internal combustion engine according to claim 7, wherein the wall members present embossed recesses in he area around said holes, the heads of the fixing bolts being countersunk in said recesses of the wall elements.

9. An internal combustion engine according to claim 1, comprising at least one wall member non-detachably connected with said supporting frame.

10. An internal combustion engine according to claim 1, comprising at least one wall member integral with the supporting frame.

Patent No. 3,7823196 Dated January 1, 1974 Inventofls) Gerhard Thien, Othmar Skatschej and Heinz Fachbach It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the' title page please insert -Claims priority on Austria;v application No. A8443/7l, filed September 29,

Signed-and jsealed this9th day of Ju1y 197'4,

(SEAL) Attest: I V Y L I MCCOY M. GIBSON; JR. I C MARSHALL DANN I Attesting Officer i Commissionerof Patents FORM PO-1050 (10-69) I 1 I usccwm 50376-p59 U.S. GOVERNMENT PRINTING OFFICE: I), O-JGS-SJ,

Patent No. 3,782,496 Dated January 1, 1974- Inventor(s) Gerhard Thien, Othmar Skatsche] and Heinz Fachbach It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the title page please insert -Claims priority on I Austria; application No. v A8443/7l, filed September 29 Signed'and sealed this 9th day of July' 1974. I

SEAL) Attest: I MCCOY M. GIBSON, JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. An internal combustion engine in a sound-proof casing comprising a supporting frame surrounding the engine and attached thereto, sound-proofing members arranged between said supporting frame and its attachments to the engine, the supporting frame being designed as a rigid frame, wall members attached to said supporting frame and forming a sound-proof casing for the engine, sound-proofing stays mounted on said engine and extending through said sound-proofing casing, said stays resting on a foundation carrying the engine.
 2. An internal combustion engine according to claim 1, comprising packing strips located between said supporting frame and said wall members and extending alongside the outer rim of the wall members.
 3. An internal combustion engine according to claim 2, comprising a supporting frame consisting of hollow sections, stiffening strips arranged on the inside of said wall members and extending alongside the outer rim of the latter, said stiffening strips adjoining the packing strips and being screwed on to said hollow sections.
 4. An internal combustion engine according to claim 3, wherein said hollow sections have a rectangular cross-section and said stiffening strips are designed as U-shaped strips with legs bent outwardly at right angles and a web portion located between the legs, the said angle-shaped legs being attached to the inside of the wall members and the web portion adjoining the packing strip.
 5. An internal combustion engine according to claim 2, wherein said wall members have an outer rim bent out Z-fashion, a first leg of this outer rim extending in transverse relation to the wall plane of the wall member, the second external leg extending in parallel relation to said wall plane, sAid packing strips being of a rectangular cross-section and each presenting a slot extending in a longitudinal direction of the packing strip and in parallel relation to the wall plane of the adjacent wall member, said second leg of the outer rim of the wall member engaging said slot of the packing strip, angle irons extending longitudinally and adjoining said packing strip, clamps provided in spaced relation to each other on the supporting frame and screwed to same, said clamps engaging the angle irons and holding the latter together with the packing strips on the supporting frame.
 6. An internal combustion engine according to claim 2, wherein said wall members have a profiled outer rim, a first section of this outer rim being bent inwardly, the second section adjoining the former section of the outer rim being bent up in the shape of a semicircle, said packing strip having a groove-like recess extending in a longitudinal direction of the packing strip and being located on the side of the packing strip facing away from said carrying frame, the section of the outer rim of the wall member which is bent up in the shape of a semicircle engaging the groove-like recess of the packing strip, clipper-shaped gripping levers arranged in spaced relation to each other on said supporting frame, a hook-shaped projection at each of the gripping levers engaging the inside of the rim section of the wall member bent up in the shape of a semicircle.
 7. An internal combustion engine according to claim 2, wherein each of the wall members consists of an essentially flat outer wall and an inner wall essentially parallel to the former, the inner wall comprising a number of outwardly bent corrugated protrusions and being attached to the outer wall by means of the corrugated protrusions, one corrugation being protruding inwardly on the inner wall of the wall member and extending in parallel relation to the outer rim of the wall member, said packing strip having a groove-shaped recess extending in a longitudinal direction of the packing strip and being arranged on the side of the packing strip facing away from the supporting frame, said corrugation engaging the groove-shaped recess of the packing strip, a number of holes being provided on said wall members in spaced relation to each other next to the corrugation, a number of tapholes in said supporting frame in alignment with said holes, fixing bolts extending through the holes and screwed in the tapholes of the supporting frame.
 8. An internal combustion engine according to claim 7, wherein the wall members present embossed recesses in the area around said holes, the heads of the fixing bolts being countersunk in said recesses of the wall elements.
 9. An internal combustion engine according to claim 1, comprising at least one wall member non-detachably connected with said supporting frame.
 10. An internal combustion engine according to claim 1, comprising at least one wall member integral with the supporting frame. 